SEOUL, March 23 (Yonhap) -- North Korea's trade with South Korea fell to about half of its trade with China in 2010 amid worsened political relations between the divided Koreas, a trade body said Wednesday.

The two Koreas exchanged US$1.91 billion worth of goods last year, up 14 percent from 2009, according to the Korea International Trade Association (KITA).

However, trade between the North and China jumped 32 percent on-year to slightly over $3.46 billion, indicating Pyongyang's growing economic dependence on its communist ally.

The proportion of inter-Korean trade to North Korea-China trade reached its peak of 91 percent in 2007 when then-South Korean President Roh Moo-hyun held a historic summit with North Korean leader Kim Jong-il, the second summit between the Koreas.

The rate dropped to 65 percent in 2008, 64 percent in 2009 and 55 percent last year, KITA said.

When only considering the amount, inter-Korean trade reached its highest level last year, but only because of increased output at a joint industrial complex of the two Koreas in the North's border town of Kaesong.

Economic exchanges between the two Koreas at Kaesong jumped 53.4 percent on-year to over $1.44 billion in 2010 while the amount of the actual trading of goods between the countries plunged 54 percent from a year earlier to $117.8 million, according to KITA.

"The gap between the amount of South-North trade and that of North-China trade will further widen unless the tension between the South and North is quickly removed, as economic cooperation between the North and China is fast increasing," said Shim Nam-seop, a KITA official in charge of inter-Korean trade.

Relations between the two Koreas quickly deteriorated after the communist North sank a South Korean warship, Cheonan, about a year ago, killing 46 South Korean sailors.

They further worsened to their lowest ebb after the North shelled a populated South Korean island, Yeonpyeong, in November, killing four people, including two civilians.